*
* ASSUMPTIONS
* -----------
+ * o Feature negotiation is coordinated with connection setup (as in TCP), wild
+ * changes of parameters of an established connection are not supported.
* o All currently known SP features have 1-byte quantities. If in the future
* extensions of RFCs 4340..42 define features with item lengths larger than
* one byte, a feature-specific extension of the code will be required.
return dccp_feat_table[idx].reconciliation;
}
+static int dccp_feat_default_value(u8 feat_num)
+{
+ int idx = dccp_feat_index(feat_num);
+ /*
+ * There are no default values for unknown features, so encountering a
+ * negative index here indicates a serious problem somewhere else.
+ */
+ DCCP_BUG_ON(idx < 0);
+
+ return idx < 0 ? 0 : dccp_feat_table[idx].default_value;
+}
+
/* copy constructor, fval must not already contain allocated memory */
static int dccp_feat_clone_sp_val(dccp_feat_val *fval, u8 const *val, u8 len)
{
* - list is sorted in increasing order of feature number (faster lookup)
*/
+/**
+ * dccp_feat_entry_new - Central list update routine (called by all others)
+ * @head: list to add to
+ * @feat: feature number
+ * @local: whether the local (1) or remote feature with number @feat is meant
+ * This is the only constructor and serves to ensure the above invariants.
+ */
+static struct dccp_feat_entry *
+ dccp_feat_entry_new(struct list_head *head, u8 feat, bool local)
+{
+ struct dccp_feat_entry *entry;
+
+ list_for_each_entry(entry, head, node)
+ if (entry->feat_num == feat && entry->is_local == local) {
+ dccp_feat_val_destructor(entry->feat_num, &entry->val);
+ return entry;
+ } else if (entry->feat_num > feat) {
+ head = &entry->node;
+ break;
+ }
+
+ entry = kmalloc(sizeof(*entry), gfp_any());
+ if (entry != NULL) {
+ entry->feat_num = feat;
+ entry->is_local = local;
+ list_add_tail(&entry->node, head);
+ }
+ return entry;
+}
+
+/**
+ * dccp_feat_push_change - Add/overwrite a Change option in the list
+ * @fn_list: feature-negotiation list to update
+ * @feat: one of %dccp_feature_numbers
+ * @local: whether local (1) or remote (0) @feat_num is meant
+ * @needs_mandatory: whether to use Mandatory feature negotiation options
+ * @fval: pointer to NN/SP value to be inserted (will be copied)
+ */
+static int dccp_feat_push_change(struct list_head *fn_list, u8 feat, u8 local,
+ u8 mandatory, dccp_feat_val *fval)
+{
+ struct dccp_feat_entry *new = dccp_feat_entry_new(fn_list, feat, local);
+
+ if (new == NULL)
+ return -ENOMEM;
+
+ new->feat_num = feat;
+ new->is_local = local;
+ new->state = FEAT_INITIALISING;
+ new->needs_confirm = 0;
+ new->empty_confirm = 0;
+ new->val = *fval;
+ new->needs_mandatory = mandatory;
+
+ return 0;
+}
+
static inline void dccp_feat_list_pop(struct dccp_feat_entry *entry)
{
list_del(&entry->node);
return -ENOMEM;
}
+static u8 dccp_feat_is_valid_nn_val(u8 feat_num, u64 val)
+{
+ switch (feat_num) {
+ case DCCPF_ACK_RATIO:
+ return val <= DCCPF_ACK_RATIO_MAX;
+ case DCCPF_SEQUENCE_WINDOW:
+ return val >= DCCPF_SEQ_WMIN && val <= DCCPF_SEQ_WMAX;
+ }
+ return 0; /* feature unknown - so we can't tell */
+}
+
+/* check that SP values are within the ranges defined in RFC 4340 */
+static u8 dccp_feat_is_valid_sp_val(u8 feat_num, u8 val)
+{
+ switch (feat_num) {
+ case DCCPF_CCID:
+ return val == DCCPC_CCID2 || val == DCCPC_CCID3;
+ /* Type-check Boolean feature values: */
+ case DCCPF_SHORT_SEQNOS:
+ case DCCPF_ECN_INCAPABLE:
+ case DCCPF_SEND_ACK_VECTOR:
+ case DCCPF_SEND_NDP_COUNT:
+ case DCCPF_DATA_CHECKSUM:
+ case DCCPF_SEND_LEV_RATE:
+ return val < 2;
+ case DCCPF_MIN_CSUM_COVER:
+ return val < 16;
+ }
+ return 0; /* feature unknown */
+}
+
+static u8 dccp_feat_sp_list_ok(u8 feat_num, u8 const *sp_list, u8 sp_len)
+{
+ if (sp_list == NULL || sp_len < 1)
+ return 0;
+ while (sp_len--)
+ if (!dccp_feat_is_valid_sp_val(feat_num, *sp_list++))
+ return 0;
+ return 1;
+}
+
+/**
+ * __feat_register_nn - Register new NN value on socket
+ * @fn: feature-negotiation list to register with
+ * @feat: an NN feature from %dccp_feature_numbers
+ * @mandatory: use Mandatory option if 1
+ * @nn_val: value to register (restricted to 4 bytes)
+ * Note that NN features are local by definition (RFC 4340, 6.3.2).
+ */
+static int __feat_register_nn(struct list_head *fn, u8 feat,
+ u8 mandatory, u64 nn_val)
+{
+ dccp_feat_val fval = { .nn = nn_val };
+
+ if (dccp_feat_type(feat) != FEAT_NN ||
+ !dccp_feat_is_valid_nn_val(feat, nn_val))
+ return -EINVAL;
+
+ /* Don't bother with default values, they will be activated anyway. */
+ if (nn_val - (u64)dccp_feat_default_value(feat) == 0)
+ return 0;
+
+ return dccp_feat_push_change(fn, feat, 1, mandatory, &fval);
+}
+
+/**
+ * __feat_register_sp - Register new SP value/list on socket
+ * @fn: feature-negotiation list to register with
+ * @feat: an SP feature from %dccp_feature_numbers
+ * @is_local: whether the local (1) or the remote (0) @feat is meant
+ * @mandatory: use Mandatory option if 1
+ * @sp_val: SP value followed by optional preference list
+ * @sp_len: length of @sp_val in bytes
+ */
+static int __feat_register_sp(struct list_head *fn, u8 feat, u8 is_local,
+ u8 mandatory, u8 const *sp_val, u8 sp_len)
+{
+ dccp_feat_val fval;
+
+ if (dccp_feat_type(feat) != FEAT_SP ||
+ !dccp_feat_sp_list_ok(feat, sp_val, sp_len))
+ return -EINVAL;
+
+ if (dccp_feat_clone_sp_val(&fval, sp_val, sp_len))
+ return -ENOMEM;
+
+ return dccp_feat_push_change(fn, feat, is_local, mandatory, &fval);
+}
+
int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
u8 *val, u8 len, gfp_t gfp)
{
{
int rc;
+ /* Ignore Change requests other than during connection setup */
+ if (sk->sk_state != DCCP_LISTEN && sk->sk_state != DCCP_REQUESTING)
+ return 0;
dccp_feat_debug(type, feature, *val);
/* figure out if it's SP or NN feature */
int found = 0;
int all_confirmed = 1;
+ /* Ignore Confirm options other than during connection setup */
+ if (sk->sk_state != DCCP_LISTEN && sk->sk_state != DCCP_REQUESTING)
+ return 0;
dccp_feat_debug(type, feature, *val);
/* locate our change request */
all_confirmed = 0;
}
- /* fix re-transmit timer */
- /* XXX gotta make sure that no option negotiation occurs during
- * connection shutdown. Consider that the CLOSEREQ is sent and timer is
- * on. if all options are confirmed it might kill timer which should
- * remain alive until close is received.
- */
- if (all_confirmed) {
- dccp_pr_debug("clear feat negotiation timer %p\n", sk);
- inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
- }
-
if (!found)
dccp_pr_debug("%s(%d, ...) never requested\n",
dccp_feat_typename(type), feature);
EXPORT_SYMBOL_GPL(dccp_feat_clone);
-static int __dccp_feat_init(struct dccp_minisock *dmsk, u8 type, u8 feat,
- u8 *val, u8 len)
-{
- int rc = -ENOMEM;
- u8 *copy = kmemdup(val, len, GFP_KERNEL);
-
- if (copy != NULL) {
- rc = dccp_feat_change(dmsk, type, feat, copy, len, GFP_KERNEL);
- if (rc)
- kfree(copy);
- }
- return rc;
-}
-
-int dccp_feat_init(struct dccp_minisock *dmsk)
+int dccp_feat_init(struct sock *sk)
{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct dccp_minisock *dmsk = dccp_msk(sk);
int rc;
- INIT_LIST_HEAD(&dmsk->dccpms_pending);
- INIT_LIST_HEAD(&dmsk->dccpms_conf);
+ INIT_LIST_HEAD(&dmsk->dccpms_pending); /* XXX no longer used */
+ INIT_LIST_HEAD(&dmsk->dccpms_conf); /* XXX no longer used */
/* CCID L */
- rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_L, DCCPF_CCID,
- &dmsk->dccpms_tx_ccid, 1);
+ rc = __feat_register_sp(&dp->dccps_featneg, DCCPF_CCID, 1, 0,
+ &dmsk->dccpms_tx_ccid, 1);
if (rc)
goto out;
/* CCID R */
- rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_R, DCCPF_CCID,
- &dmsk->dccpms_rx_ccid, 1);
+ rc = __feat_register_sp(&dp->dccps_featneg, DCCPF_CCID, 0, 0,
+ &dmsk->dccpms_rx_ccid, 1);
if (rc)
goto out;
/* Ack ratio */
- rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_L, DCCPF_ACK_RATIO,
- &dmsk->dccpms_ack_ratio, 1);
+ rc = __feat_register_nn(&dp->dccps_featneg, DCCPF_ACK_RATIO, 0,
+ dmsk->dccpms_ack_ratio);
out:
return rc;
}
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff